Stress modulates declarative learning. Only a few studies have examined the influence of stress on non-declarative learning. Here, we examined the effects of a stressor, that significantly affects declarative learning, on a non-declarative perceptual learning task. On day one, participants performed a texture discrimination task. Following learning, participants submersed their forearm and hand in either ice-water or lukewarm water. The ice-water condition has previously been shown to improve declarative learning (Cahill, Gorski & Le, 2003). On day two, participants returned for a subsequent session with the same task. Only participants in the ice-water group had significantly elevated cortisol levels. However, contrary to similar declarative learning studies, we found no effect of increased stress on perceptual learning. These results suggest a functional segregation in the effects of stress hormones on cortical plasticity related to low-level perceptual learning and high-level declarative learning.